Process of obtaining phosphatides from soapstock



Patented Apr. 27, 1937 PROCESS OF OBTAINING PHOSPHATIDES FROM SOAPSTOCKBenjamin H Thurman, Yonkers, N. Y., assignor to Refining, Inc., Reno,New, a corporation of Nevada No Drawing.

Original application September 6,

1933, Serial No. 688,361. Divided and this application February 12,1935, Serial No. 6,260

3 Claims.

This invention relates to the recovery of phosphatides from soapstockthat is obtained in the purification of cotton seed oil. This soapstockis customarily obtained by treating the cotton seed oil with causticalkalies or alkaline carbonates or phosphates or other reagents thatwill saponify the free fatty acids in the oil and then separating thesoapstock from the oil. This is a division of my application, Serial No.688,361, filed Septem- 10 her 6, 1933.

It has been found that the soapstock obtained from cotton seed oil inthe usual way, contains up to as high as about of phosphatides.

These phosphatides have heretofore been regarded as deleteriousimpurities in the soap stock.

By the present invention the phosphatides are removed in large measureor substantially entirely from cotton seed oil soapstock in such a waythat they do not contain an appreciable or seriously objectionableamount of injurious impurities or discoloring materials.

In carrying out the invention the cotton seed oil soapstock is treatedwith a solvent for the soapstock. Acetone, for example, may be used 5for this purpose as it will dissolve and remove the soap, free. oil andwater leaving the phosphatides as a residue when the solution isfiltered or centrifuged. Other soap solvents, such as methyl acetate,for example, in which the phosphatides are insoluble or diificultlysoluble, may be used instead of acetone for this purpose.

The following are given as specific examples of carrying out theinvention, but it is to be understood that these examples are notexhaustive and 35 that the invention is not restricted to any particularsolvent or proportion mentioned or to. the temperature or timespecified.

Example 1.-About one part by volume of cot ton seed oil soapstock wasagitated with five parts 40 of acetone for a few minutes at roomtemperature and the mixture was filtered. The solids left on the filterwere for the most part phosphatides and amounted to about 10% of theweight of the soap stock.

45 Example 2. The same amount of methyl acetate was used as the amountof acetone in Example 1 and substantially the same result was obtained.

After the phosphatides have been separated 50 from the soapstock, asdescribed above, they should be purified to remove extraneous ordeleterious matter, leaving a purified residue that is very valuable inthe arts for many useful purposes. The solid content of the masscontaining 55 phosphatides that is obtained from the soap stock (c1.zoo-99.20)

contains about 60 or 70% of the valuable phosphatides from which a largeportion or substantially all of the remaining solids or deleteriousphosphatides are of such a character that they do not have anobjectionable taste or odor and do not become rancid for a long timeeven when exposed to air, or certain ingredients which appear to aid inpreserving the phosphatides may have been removed from the soap stockwith the phosphatides and are not removed from the phosphatides duringthe purification step. The deleterious impurities may be removed fromthe phosphatide mass or residue by washing the phosphatides or solidswith water, or an aqueous matter can be removed. The remaining purifiedof sodium chloride in the water has been found to be satisfactory. Anaqueous salt solution apparentlyhas a solvent action on some of theglobulin and albuminoid substances in the phosphatide mass so that theyare removed during the washing step. Also, the remaining insolublephosphatides are left in small particles. The

phosphatides may be Washed repeatedly with It has also been found thatwater can be used for washing the phosphatides without having saltdissolved in it, provided the pH of the water is kept sufiiciently low,say about pH 3 to prevent emulsification. Chlorine ions appear to beparticularly advantageous in preventing emulsification, although otheracids and acid salts, such as tartaric, citric, sulphuric acids andsodium salts and sodium acid, salts, for example, which will lower thepH of the solution can be used. However, hydrochloric acid has thus farbeen found to be the most satisfactory for this purpose.

The purified dry product may be dissolved in a non-solidifying oil, suchas sunflower oil, sesame oil, or soya bean oil and the substances thatare insoluble in these oils may be centrifuged or filtered out. Thepercentage of oils used for sa-d M,

dissolving the product may be or more of the weight of the product thatis dissolved in the oil.

Some of the characteristics which distinguish the phosphatides orproduct obtained, as described above, from cotton seed oil, from similarproducts are as follows:

(a) This product contains approximately the same percentage ofphosphorousnamely about 1.8%, calculated on a dry basis, as theprecipitate that precipitates out of the oil after it has been allowedto stand for a long time without theadditlon of a reagent.

(b) The iodine number of the purified product is approximately 60, whilethe iodine number of the purest vegetable lecithin products now known isabout 90.

(0) Fatty acids obtained from this purified product or phosphatides havean iodine number of about 95 while the iodine number of cotton seed oilis about 108 and the iodine number of soya bean oil, as well as thefatty acids from lecithin obtained therefrom, is about 125. The lowiodine number of the product of this invention and the fatty acidsobtained from it probably explains, at least in part, why the .productof this application will keep such a long time or has very littletendency to absorb air and become rancid.

(d) The product or phosphatides of this invention may be dissolved inhigh boiling oils, suchas sunflower seed .oil and heated to 440 F.without changing color very much and without having a very noticeableamount of objectionable odor or taste imparted thereto, while lecithinobtained from soya beans and heated in the same way has imparted to it avery dark or almost, black color and a very nauseatingodor andunpalatable taste, resembling the odor of 40 fish or paint.

(e) A trace of gossypol or rafiinose has been found in'the phosphatides,but is not present in suflicient amounts to interfere with theedibleness of the phosphatides,

The purified phosphatides obtained from cotton seed oil as describedabove are useful for many purposes, some of which may be mentioned; asan agent for reducing the viscosity of sugar, chocolate and fatcoatings; a small amount, say 0.3% thereof, added to chocolate preventsthe same from blooming after several hours even in warm weather; aboutone-half of 1% thereof added to vegetable oils greatly decreases thetendency of these oils to become rancid even at temperatures up to 150F. or higher over an extended period of time; about 1% or less thereofadded to dressings, such as mayonnaise, materially increases the keepingqualities of the same and prevents or greatly retards rancidity; lessthan 1% thereof added to margarine prevents the same from foaming orspattering when heated, thus permitting food, such as eggs, to bebrowned when fried therein;

less than 1% added to deep frying oils or fats prevents or greatlyretards rancidity and acquisition of bad flavors or odors even attemperatures somewhat above 400 F.; a small amount thereof added to fatsused in making caramels improves the quality of the caramels withoutimparting any objectionable taste.

It has been found that mayonnaise containing soya bean oil which wouldbecome rancid and develop a characteristic odor in a few days willremain fresh when about 0. %ths percent of the product or phosphatidesof this invention is added. This product seems to act as an anti-oxidantor'at least prevents development of the objectionable odor or flavor inthe soya bean oil. This may possibly be due to the prevention of theaction of enzymes or bacteria in the soya bean oil used in makingmayonnaise dressing. When about 0.1% of this product is added to butterit prevents formation of strong odors even when the butter is exposed tothe atmosphere for a long time and it also prevents water from leakingout'of the butter, probably because'it is a good emulsifying agent forthe butter. This product is-also valuable as an apparent anti-oxidant inthe manufacture of rubber, as well as an excellent anti-oxidant when iput in linseed oil varnish that is to be used for painting rubber goods.The addition of even less than 1% of the product to fats or oils thatare used for frying vegetable products greatly reduces the tendency ofthese fats or oils to split and form products that are characteristic ofoverheated fats, thus imparting substances to the food products thatwould cause them to become rancid. Food products,- such as potato chipsthat have large surfaces are especially prone to become rancid veryrapidly by oxidation. The use of the product of this invention in fatsor oils for frying such vegetables protects the products and permits thesame fatty oil to be used repeatedly for frying them.

I claim:

1. The process of recovering phosphatides, which comprises treatingcotton seed oil soapstock with a soap and oil solvent, separating theinsoluble products, and washing them with an aqueous solution having apH of not more than about 3.

2. The process of recovering phosphatides, which comprises treatingcotton seed oil soapstock with a soap and oil solvent, separating theinsoluble products, and Washing them with an aqueous solution containingchlorine ions and having a pH of not more than about 3.

3. The process of recovering phosphatides, which comprises treatingcotton seed oil soapstock with a soap and oil solvent in whichphosphatides are substantially insoluble, separating the insolubleproducts and washing them with an aqueous solution having a pH of notmore than about 3. BENJAMIN H. THURMAN.

